Go to Star Rewards -> Item -> Shino Pill * 15
You will find the sign Cancer in BLUE colour.
It's orignally a BROWN coloured sign, thus you won't be able to exchange.
I've got 30 cancer signs as blue and 30 as brown but they are actually only 30 not 60!
You know what I mean?
It means the Sign Cancer in Blue (Never Existed) and should be changed from BLUE to BROWN.
Please fix this bug.
I've got 30 cancer signs, that is 450 Shino pills that I can't exchange because of it.